摘要
采用恒电流Ｅ－ｔ曲线与旋转盘环电极方法研究了α黄铜（Ｃｕ３２Ｚｎ）在酸性Ｎａ２ＳＯ４和ＨＮＯ３稀溶液中的阳极溶解行为，得到的典型Ｅ－ｔ曲线上存在几个特征区，证明在较低电流密度条件下的初始阶段只存在Ｚｎ的选择性溶解。用恒电位法研究了Ｃｕ３２Ｚｎ选择性溶解过程，得到了按抛物线衰减的暂态扩散曲线，由ｉ－ｔ－１／２直线关系求得了不同介质中Ｃｕ３２Ｚｎ中Ｚｎ的固相扩散系数Ｄ在１０－１６～１０－１３ｃｍ２·ｓ－１数量级，发现中性介质中测出的Ｄ值比酸性介质中要大两个数量级。
The selective dissolution of zinc in brass Cu 32 Zn in acidic sodium sulphate and dilute nitric acid solutions was investigated by galvanostatic polarization and RRDE methods. Obtained potential time relation indicated that selective dissolution of zinc occurred during initial stage at small current density. The kinetics of selective dissolution of zinc in Cu 32 Zn in several media containing SO 2- 4 or NO - 3 were studied by potentiostatic transient method. The current time curves followed the parabolic rate law. The plot of i against t -1/2 was a well straight line. In terms of slope of i t -1/2 straight line, the diffusion coefficients of zinc in Cu 32 Zn were calculated to be of the order of 10 16 ～10 13 cm 2·s 1 in studied media. Furthermore, the nature and acidity of medium significantly affected diffusion coefficient value, which was discussed based on the vacancy diffusion mechanism.
出处
《腐蚀科学与防护技术》
CAS
CSCD
1996年第3期190-194,共5页
Corrosion Science and Protection Technology
基金
国家自然科学基金资助项目
金属腐蚀与防护国家重点实验室课题
关键词
黄铜
脱锌
选择性溶解
固相扩散
扩散系数
brass dezincification, selective dissolution, solid state diffusion, diffusion coefficient
